Groton - Groton is bracing for a loss of more than $2 million from its tax rolls with news that Pfizer plans to demolish its former research headquarters, known as Building 118.

Just when that will happen remains unknown and depends on how quickly the pharmaceutical giant can acquire a demolition permit and get to the work of tearing down the 750,000-square-foot complex off Eastern Point Road.

Pfizer says that will happen in the next few months, despite what is typically a lengthy process to prepare the site and assure building officials that all of the necessary building codes are met and safety measures are in place.

Carlton M. Smith, the zoning and building official for the City of Groton, said Pfizer has not yet applied for a demolition permit.

The Planning and Zoning Commission, however, did approve a coastal site plan review for Pfizer in September, a precursor for the permit that is required because a portion of the complex falls within 1,000 feet of the Thames River. The coastal site plan contained things such as erosion control and other measures to protect the coastline during demolition.

Smith said that Pfizer must follow relevant state building codes. The demolition plans will be reviewed both by his office and by the fire marshal's office.

By the time the permit is issued, Smith said, an applicant would have worked out plans for things such as shutting off utilities and asbestos mitigation, if needed. In Pfizer's case, Smith said, that would include, for example, a plan showing how it would separate the walking bridges connecting sections of Building 118 to other Pfizer buildings.

The disconnection of utilities itself, he said, would be a large project considering "this is on a much larger scale than a single-family home." Safety inspections also would have to be performed during the process.

Town Manager Mark Oefinger said Pfizer notified town officials at the beginning of the year that they were seeking demolition contractors. He believed at the time, and still holds out hope, he said, that there has been enough interest in the complex to delay Pfizer's plans.

Oefinger said he doesn't expect an immediate loss of tax revenue and thinks it unlikely that the building will be completely gone by year's end. Since assessments for next year's grand list are completed by Oct. 1, Oefinger said, he expects the impact will come in fiscal year 2015.

The same is the case in the city, which will suffer an estimated $500,000 tax loss, according to Mayor Marian Galbraith.

Pfizer was a factor in the drop in the 2012 grand list, which dipped by 1.3 percent from 2011. Most of the grand list loss was attributed to the $46.7 million drop in personal property values, Pfizer's included, he said.

Pfizer, however, remains far and away the town's largest taxpayer with a total net assessment of $550 million. Electric Boat, the second-highest taxpayer, was assessed at $214.3 million, and Ledges Apartments came in third with a $21.4 million in assessed value.

Oefinger said it may be that Pfizer continues to pull personal property from the building, which will mean tax revenue losses. He said the last time he was at the facility, about a month ago, there still were staff on site.

Town records show the Building 118 complex of seven interconnected buildings is valued at $123.7 million, with an assessed value of $86.6 million.

Despite the sting of Wednesday's announcement, made doubly painful because there was an interested buyer, Oefinger said he understands it must costs hundreds of thousands of dollars to maintain the complex.

"This doesn't make any sense from an economic development perspective, but at the end of the day, it is Pfizer's building," Oefinger said. "For whatever reason, the cord has been pulled."

With the time it will take to line up the permits to start demolition, "Why not go back to the table?" Galbraith asked.

"I still hope they'll reconsider. We have a legitimate developer that hasn't walked away," she said. "They are not just eliminating a building, they're eliminating a opportunity for this region."